Autonomous electro-optical framing camera system with constant ground resolution, unmanned airborne vehicle therefor, and methods of use

Abstract

An aerial reconnaissance system generates imagery of a scene that meets resolution or field of view objectives automatically and autonomously. In one embodiment, a passive method of automatically calculating range to the target from a sequence of airborne reconnaissance camera images is used. Range information is use for controlling the adjustment of a zoom lens to yield frame-to-frame target imagery that has a desired, e.g., constant, ground resolution or field of view at the center of the image despite rapid and significant aircraft altitude and attitude changes. Image to image digital correlation is used to determine the displacement of the target at the focal plane. Camera frame rate and aircraft INS / GPS information is used to accurately determine the frame to frame distance (baseline). The calculated range to target is then used to drive a zoom lens servo mechanism to the proper focal length to yield the desired resolution or field of view for the next image. The method may be performed based on parameters other than range, such as aircraft height and stand off distance.

Description

This invention relates generally to the art of aerial reconnaissance photography, and more particularly to a reconnaissance camera system having an electro-optical imaging sensor or array with zoom lens capability that automatically and autonomously achieves desired ground resolution or field of view objectives for the reconnaissance mission. The invention also relates to a method of using such a sensor to generate images with desired ground resolution, field of view, or image interpretability objectives regardless of the changes in velocity or height of an aerial reconnaissance vehicle incorporating the sensor. The invention also relates to an unmanned aerial vehicle that incorporates the reconnaissance camera system that operates autonomously to meet reconnaissance mission objectives. The camera system can be pre-programmed to capture high resolution images with desired, e.g., constant, ground resolution, field of view or image interpretability value without any human or operator ...

AI Technical Summary

Problems solved by technology

In military reconnaissance, it is frequently not sufficient to just provide an image of the target itself, but imagery of the surrounding terrain is required as well.

UAVs have been developed by the United States and other countries for military and civilian purposes and are gaining rapidly in their acceptance as a viable mission platform because of their small size, inexpensive procurement and operating cost, limited or no human risk and in some cases, long endurance.

However, these advantages also place unique restrictions on the payloads that they carry, including the reconnaissance cameras.

However, in the case of high altitude, long endurance UAVs, the man-in-the-loop up-link control is no longer always available.

As such, the patent is not truly an autonomous system and would not be suitable for an autonomous system or an UAV type of environment.

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